docs: async def is_locked(self, resource):
          """
          Checks if the resource is locked by any redlock instance.
  
          :param resource: The resource string name to lock
          :returns: True if locked else False
          """
  
          successes = await asyncio.gather(*[
              i.is_locked(resource) for
              i in self.instances
          ], return_exceptions=True)
          successful_sets = sum(s is True for s in successes)
  
          locked = True if successful_sets >= int(len(self.instances) / 2) + 1 else False
  
          return locked